In recent years, image pick-up apparatuses using a solid-state image pick-up device such as a digital still camera are being popularized. Further, with popularization of digital still cameras, there is required a zoom lens having excellent compactness and having high image formation performance, while covering the range from a super-broad angle side up to the telescopic side by a single lens.
For example, in the zoom lens described in the Japanese Patent Application Laid Open No. 1995-261084 publication, a zoom lens configuration including a negative lens group as a preceding lens group is used to realize a broad angle of the zoom lens. However, in the zoom lens described in the Japanese Patent Application Laid Open No. 1995-261084 publication, the magnification ratio is small. The magnification of about two times or three times is a limit. Realization of high magnification is difficult.
On the other hand, in the zoom lenses described in the Japanese Patent Application No. 1997-5629 publication, and the Japanese Patent Application No. 1995-318805 publication, the zoom configuration including a positive lens group as the preceding lens group is used to realize high magnification of the zoom lens and broad angle thereof.
However, in the Japanese Patent Application Laid Open No. 1997-5629 publication and the Japanese Patent Application Laid Open No. 1995-318805 publication, a photographic picture angle of about 80 degrees is a limit. As a result, realization of a broader angle is difficult. Moreover, even if realization of a broader angle can be attained, the number of lenses constituting the first lens group having a large lens diameter is increased so that miniaturization is not sufficient, cost is increased and weight also becomes heavy. This is not preferable.
In view of the above, an object of the present invention is to provide a zoom lens including a broad picture angle of 60 to 100 degrees as a photographic picture angle of a wide-angle end state, and having a magnification ratio of about three to six times, small front optical gem diameter and excellent compactness, and high image formation performance, which is used in video camera or digital still camera; and an image pick-up apparatus comprising such zoom lens.